Japanese Laid-Open Patent Publication No. 10-39560, for example, discloses an image forming apparatus, such as a laser printer, wherein a process cartridge, which is detachably attachable to an image forming apparatus, has a photosensitive drum for carrying a toner image. The image forming apparatus has a transfer roller for transferring the toner image, being carried on the photosensitive drum, onto a sheet. When the process cartridge is attached to the image forming apparatus, the photosensitive drum contacts the transfer roller to form a nip portion, which is where the toner image, carried by the photosensitive drum, is transferred onto the sheet when a transfer bias is applied to the transfer roller.
By not including the transfer roller in the above-described process cartridge, the size of the process cartridge can be reduced. An image forming apparatus that accommodates such a process cartridge may also have a smaller-sized attaching/detaching opening and/or a smaller-sized attaching/detaching path through which the process cartridge passes during attachment/detachment of the process cartridge to/from the image forming apparatus. As a result, the overall size of the image forming apparatus may also be reduced.
The image forming apparatus disclosed in Japanese Laid-Open Patent Publication No. 10-39560, for example, includes, however, sheet-guiding members that are disposed in the path. When attaching/detaching the process cartridge to/from the image forming apparatus, the process cartridge must be guided along the path such that the photosensitive drum does not interfere with and/or become damaged by the sheet-guiding members. In order to reduce, and preferably prevent, interference between the photosensitive drum and the sheet-guiding members, a space, which is large enough to avoid the sheet-guiding members, needs to be provided in the attaching/detaching opening and the attaching/detaching path. If, however, such a larger space for the attaching/detaching path and/or the attaching/detaching opening must be allocated in the image forming apparatus, the size advantage acquired by providing the transfer roller on the image forming apparatus instead of the process cartridge is reduced and/or lost.